Electric switch



Au 28, 1%3. mama? W. H. HARRINGTON ELECTRIC SWITCH Filed Nov. 27, 1922 ,4 TTORNE Y5 Patented Aug. 28, 1923.

UNITED STATES 1,466,507 PATENT OFFICE.

WILLIAM. H. EARBINGTON,/OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE ARROW ELECTRIC COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CON- NECTICUT.

ELECTRIC SWITCH.

application filed November 27, 1922. Serial No. 603,583.

Toall'whom it may concern:

Be it known that. I, WILLIAM H. HARRING- TON, a citizen of the United States of America, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Electric Switches, of which the following is a specification.

My invention relates to electric switches, and particularly to the escapement mechanism for a rotary snap switch. The object of my invention is to provide an escapement device of simple and economical construction, which is not only eflicient and certain in its operation, but also adaptedv for the control of the drive of the switch blade element in either direction: of rotation.

In the accompanying drawings- Fig. 1 is a vertical section through a rotary snap switch, in which my invention is embodied in one form;

F Fig. 2 is a broken section on the line 2--2,

ig. 3 is a dropped perspective of the escapement mechanism and associated elements;

Fig. 4 is a perspective view of the operating cam and the associated detaining parts;

ig. 5 is a plan of one of the escapement plates; and

Fig. 6 is a section on the line 66, Fig. 2.

While the present mechanism may be used to advantage in rotary snap switches of various types, I have shown it in a reversible switch of the heater type. The switch mechanism is mounted upon an insulating base 7, and comprises a switch spindle 8 rotatable in either direction by the thumb piece 9. The switch blades 10 free on the spindle, have rigid therewith a dog plate 11, the lug 12 of which is engaged between the offset ends 13 and 14 of the switch spring 15 which is torsionally stressed by the lug 16 of the spring cage 17 fast on the spindle 8. The spindle passes down through the switch blade carrier 18 and is notched at 19 adjacent its lower end to receive a U-shaped retaining washer 20 which underlies the es capement mechanism and serves to retain the spindle against outward displacement.

The escapement mechanism to which my invention particularly relates is operated from the switch spindle 8 through. a cam disk 21, centrally slotted at 22 to fit upon nd engage the laterally sheared lower end 23 of the spindle. At appropriate points around the periphery of the disk 21 are cam ofl'sets 24 by which the two detent pawls 25 and 25 are operated. The pawls are laterally notched to receive and engage between the upper and lower lugs 26 and 27 so formed, the cam margin of the disk 21. In order to facilitate the operative engagement between these parts, the lugs 26and 27 may be of rounded contour.

The cam disk 21 is arranged between upper and lower plates 28 and 29 which are apertured in register at 30 and 31, respectively, on divergent/radii to accommodate the detent pawls 25 and 25", and to permit the latter to play freely therein under the control of the rotating cam disk 21. The upper plate 28 of the frame preferably lies in a plane and affords a fiat upper bearing I surface upon which rides the detent plate 32. The latter rotates with the switch blade carrier 18 through the interengagement of the studs 33 in the holes 34 in the bottom flanges of the carrier. The detent plate 32 has opposite arcuate areas 35 and35 corresponding approximately in arcuate extent to the angle between the adjacent faces of the detent pawls 25 and 25", so that in certain positions of-the switch, one or the other of the segments is engaged between the pawls 25 and 25 The arcuate interspaces 36 between circumferentially adjacent faces of the lugs 35 is of such greater arcuate extent that in certain other positions of the switch, the pawls are engaged between these faces of the lugs 35, as illustrated in Fig. 2.

The cams 24 of the disk 21 are so shaped as to cause the pawls to play through the plate 28 on the rotation of the s indle, and in such manner that when one o the pawls is depressed to free the detent 32, the other pawl is raised above the plate 28 to form a sto which halts the detent in the next suc- 21 to take a position in which both pawls 25 and 25 rise above the plate 28 and into obstructin position with respect to the detent 32. dictation of the latter in either direction is thus obstructed.

The plates 28 and 29 are s aced apart to accommodate between them t e rotary cam disk 21, and this may be readily accomplished by providing the lower plate 29 with offset lugs 37 which register with lugs 38 of the bearing plates 28, and by which both upper and lower plates may be secured to the insulating base 7 by bolts 39 passing through registering apertures 40 in the superposed lugs. Exact registry of the pawl-receiving slots 30 and 31, and a very secure mounting may be attained by providing the upper plate 28 with a tapped boss 41, which passes through the hole 40 in the lug 37 of the lower plate. Not only are the plates thus centered with respect to each other, but a long bearing is afforded for the securing screw 39. Moreover, the engage ment of the boss 41 in the holes 40 of plate 29 holds the plates together as an assembly unit during the manufacture of the switch. The cam disk 21 is retained in position by the offset lugs 37 of plate 29.

It may be noted that the spindle 8 does not pass through the insulating base 7 as has heretofore been common practice, but has a guide bearing at its lower end in'the apertures 42 in the plates 28 and 29, and in a steadying bridge 43 arranged toward the upper end of the spindle and bet-ween the spring cage 17 and the insulating lining 44 of the switch cover 45. The bottom support of the spindle is afforded by'the cam plate 21, the upper face of which engages the shoulder 46 afforded by the lateral shearing of the spindle at 23 to fit the hole 22 in the cam plate. The spindle thus has a step bearing on the base plate 29, and a plurality of uide bearings in the plates 28 and 29 and liridge'43. A very steady mounting for the spindleis thus attained. It will. be noted further that the supporting lugs 37 and 38 of the plates 28 and 29 rest upon the depressed seats 47 in the base, and that the side walls of the seats serve to confine the lugs and, if sufliciently accurately shaped to the latter, relieve the securing screws 39 of the strains imposed upon them by the successive blows against pawls 25 and 25 by the detent plate 32 under the throw-of the switch spring.

The operation of the mechanism will be readily understood. Assuming the parts to be in theposition shown in Fig. 2, the pawls 25 and 25 are engaged between circumferentially adjacent faces of the arcuate lugs 35 of the detent plate 32. Upon rotation of the spindle 8 by the thumb piece 9, the cam plate 21 is driven regardless of the direction of rotation of the spindle. Assuming the rotation of the spindle to be clockwise, the pawl 25 is gradually ,forced down as the spindle is rotated, while the pawl 25 is maintained in raised position. Upon the depression of the pawl 25 below the surface of the bearing plate 28, the detent. 32 is released and the spring 15 now' under its greatest stress, throws the switch blade carrier, and with it the detent 32, to its next succeeding position, in which the lug -35 of the detent plate impinges against the pawl 25, and is halted thereby, together with the switch blade carrier. the spindle, its slight reverse rotation under the influence of the spring 15, which thus brings the spring-engaging lugs 12 and 16 into radial alignment, causes the pawl 25 to again rise through the plate 28 and'engage the opposite side of the arcuate lug 35 of the detent plate. The mechanism is now in position for another operation of the switch by the rotation of the spindle in either direction.

The construction shown is simply manufactured since all of the parts ma be struck from sheet metal; they are rea ily assem- Upon release of bled, not only with respect to each other, but

upon the insulating base 7 of the switch. The action of the cam 21 is positive and may be exactly timed. The pawls 25 and 25? are firmly supported by the plates 28 and 29, and are sufficiently rugged to withstand the blows imposed on them.

Various modifications in detail of contour and arrangement of parts will occur to those skilled in the art, without, however, departing from what I claim as my nvention.

ll claim- 1. An escapement mechanism for a rotarvsnap switch, comprising a rotary switch spindle, a switch blade member freely mounted thereon, a switch-operating spring operatively interposed between said s indle and switch blade member, stationary base plates in which said spindle is journalled, a cam arranged between said plates and fast with the spindle, a plurality of detents engaged by said cam and moved thereby through said plates int-o freeing and detaining positions, together with a member rotating with the switch blade member and cooperating with said detents. I

2. In an electric switch a pair of base plates spaced apart, a cam disk arranged between said plates, detent pawls playing freely through said plates and engaged by said cam, together with a switch spindle journalle-d in said plates and operating said 3. In an electric switch, a pair of base plates spaced apart, a cam accommodated between said base plates, detent pawls playing freely through and guided in said base plates and operatively engaged by the cam,

a spindle journalled in said plates and operating the cam, a Switchblade member freely mounted on said spindle, an escapement member rotatingjwith saidswitch blade member and bearing on one of said spaced base plates, said escapement member having means cooperating with said cam operated the body thereof to space the latter from.

the cooperating plate, a cam accommodated between said plates. and detent pawls playing freely through said plates and engaged by said cam, said pawls being arranged on diverging radii from the axis of the spindle bearing aperture.

5. In a rotary snap switchpan assembly unit comprising a pair of spaced plates pierced in register to accommodate a rotary switch spindle, a. cam arranged between said plates and adapted to be engaged for rotation by said switch spindle, and detent pawls working freely through said plates and engaged forvoperation by said cam.

.6. In a rotary snap switch, an assembly unit comprising a pair of. spaced plates pierced in register to accommodate a rotary switch spindle. a cam arranged between said plates and adapted to be engaged for rotation by said switch spindle. and detent pawls working freely through said plates and en gaged for operation by said cam. together with juxtaposed lugs integral with said plates and pierced in register to receive securing screws.

7. In a rotary snap switch, an assembly unit comprising a pair of spaced plates pierced in register to accommodate a rotary switch spindle, a cam arranged between said plates and adapted to be engaged for rotation by said switch spindle, and detent pawls working freely through said plates and engaged for operation by said cam, together with juxtaposed lugs integral with said plates and pierced in register to receive-securing screws, said detent paWls being arranged on divergent radii from the axis of the spindle-receiving perforations.

8. In a rotary snap switch, an escapemen't' mechanism comprising a pair of spaced plates pierced in register to accommodate detent pawls, andbosses on one of said plates entering apertures in the other of said plates to position the latter accurately with respect to each other.

9. In .a rotary snap switch, an escapement mechanism comprisinga pair of spaced plates pierced in register :to accommodate detent pawls, and bosses on one of said plates entering apertures in the 0th r of said plates to position the latter accurately with respect to each other, said bosses being pierced to receive securing screws.

10. In a rotary snap switch, a pair of superposed spaced plates, a cam arranged between said plates, said plates and cam being pierced in register to receive a switch spindle, means for retaining the cam against lateral escapement, detent pawls engaged by said cam, said plates being pierced in .register to guide said support and detent pawls.

In testimony whereof I have signed my name to this specification.

WILLIAM H. HARRINGTON. 

